Preheat oven to 180 degrees C. Grease a 23x12cm loaf tin.
Combine the flour, sugar, salt, baking powder and bicarb soda. Add the cranberries and walnuts and stir to coat with flour. Mix together the egg, oil, orange juice and grated orange rind in a separate bowl. Pour the egg mixture into the flour mixture, and stir until just blended. Spoon the batter into the prepared loaf tin.
Bake for 50 minutes in the preheated oven, or until a skewer inserted near the centre comes out clean. Cool in tin for 10 minutes, then remove to a wire rack, and cool completely.